Give a reaction between two nucleons, similar to *ge*s1* g hvvmEq. 32-4, that could produce a s*1*gm hgvve*$\pi^0$.

  If a proton is moving at very high spe0bbi 5)07asell whd.w ed, so that its kinetic energy is much greater than its rew5a b0ld. 0 i7bws)lehst energy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made up of the antiparticles to the constituentiklpi2t4nf. 5gy8 go .s of normal atoms, consist of? What might happen if antimatter, made of such antiatoms, came in coip k i8fntlg4.5.2yog ntact with our normal world of matter?

What particle in a decay signalsby+rqk vezaa :pcrl6 ,,xe*g*m6i.p :3sba0b the electromagnetic interaction?

Does the presence of a neutrino among the decay productu ;i/ss5)afy+3cw2 gj.qir dfs of a particle necessarily mean that the decay occurs via the weak interaction? Do all decays via the weak interaction pro d uffr /wigs.53y+aj;2ic )sqduce a neutrino? Explain.

Why is it that a neutron decays via thej7s tc bil*lk4v7;br, weak interaction even though the neutron and one of its decay products (proton) are strongly intkr vj7lcl7sbt *bi, ;4eracting?

Which of the four interactions (strong, :m ct/pfub;e3s0u odh-ql-0w electromagnetic, weak, gravitational) does an electron take part in? A neutrino? A proton?fpd 0-e 0c:mu olq;3/-thwusb

Check that charge and baryon number are conserved in each of the decays invu)kr vk,l;m3 -f, kte Table 32k ;kvmf kl-,vu3r,) te-2.

Which of the particle decays iay/xh+ gk)juloiu c td,9 ,;q5n Table 32-2 occur via the electromagnetic interactiojo y/uduat),;+g kxh, ci9 q5ln?

Which of the particle decays in Table 32-2 occur by the weak n vam07 scwz,9interaction?

By what interaction, and why, does xl3l)f04q(au3nek yi$\Sigma^0$ decay to $\Lambda^0 + \gamma$? What about $\Xi^-$ decaying to $\Lambda^0 + \pi^-$?

The $\Delta$ baryon has spin $\frac{3}{2}$, baryon number 1, and charge states $Q = +2, +1, 0, -1$. Why is there no charge state $Q = -2$?

Which of the particle decays in Table5 6ewm gv3- zhxdu4alyt-36az 32-4 occur via the electromagnetic interaction346 z6w3x gym- ahd luaz-evt5?

Which of the particle decays in Table 32-4 occur by the wjyn,bqap9 3 l+eak interaction?

Quarks have spin $\frac{1}{2}$. How do you account for the fact that baryons have spin $\frac{1}{2}$ or $\frac{3}{2}$, and mesons have spin 0 or 1?

Suppose there were a (f+kht6r+cghn h b vj: 3:yn7skind of "neutrinolet" that was massless, had no color charge or elervn7kh::+b3h g (yns+tjcfh6 ctrical charge, and did not feel the weak force. Could you say that this particle even exists?

  Is it possible for a particle8op:v7kr8/ kiczj*an* i2 vxq to be both
(a) a lepton and a baryon?  ----待选择----yesno 
(b) a baryon and a hadron? ----待选择----yesno 
(c) a meson and a quark? ----待选择----yesno 
(d) a hadron and a lepton?  ----待选择----yesno 
Explain.

Using the ideas of quantum chromodynamics, would it be possible to fin pehfe1( mh. a;tt;k kwd+j,6sd particles made up of two quarks and no antiquarks? pwk (tt+eja.6kh1h dfse m,;;What about two quarks and two antiquarks?

Why do neutrons decay when they are free but not when they are inside thqd1:. 4 ca7vxq.5ry idffo8ph e nucleuvfdc1h.dqxy.pq:8f45 o ai r7s?

  Is the reaction $e^- + p \to n + \nu_e$ possible? Explain.  ----待选择----yesno 

Occasionally, the $\pi^+$ will decay by the following reaction: $\pi^+ \to e^+ + \nu_e$. Which of the four forces in nature is responsible for this decay? How do you know?

  What is the total energy of a proton whose kinetic energy is 6.35 GeV?b87o+b wosg-u    GeV

  Calculate the wavelength of 35-Geh tmy41* ju:f rf5f* r)xfeqs5V electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotron in wym7fq d98c w8f, *siwgx/ 3vbdhich protons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revolution for a vewstv 9b g;c2yw( r0bf-ry high-energy proton in the 1gf0trv2- ;wb9(ybs c w.0-km-radius Fermilab accelerator? T =     $ \times 10^{-5}\ \text{s}$

  If $\alpha$ particles are accelerated by the cyclotron of Example 32-2, what must be the frequency of the voltage applied to the dees? $f$ =    $ \times 10^7\ \text{Hz}$

  (a) If the cyclotron of Example c+o9gkm z0a,s 32-2 accelerated $\alpha$ particles, what maximum energy could they attain? What would their speed be? KE =    v =    $ \times 10^7\ \text{m/s}$
(b) Repeat for deuterons ($^2\text{H}$).KE =    v =    $ \times 10^7\ \text{m/s}$
(c) In each case, what frequency of voltage is required? $f$ =    Hz

  Which is better for picking out details of tu:cvns3ry v+ 0he nucleus: 30-MeV alpha particles or 30-MeV protons? Compare eacu+v scv0:y 3nrh of their wavelengths with the size of a nucleon in a nucleus.  ----待选择---- alpha particles protons 

  The voltage across the dees of a cyclotron is + b o.7f,ai fm:,dn;m1meyfg -f )kgdn55 kV. How many revolutions do protons make to reach a kine fof1;gmd,+gb-e:d.)kmyf afnin,7m tic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the waveleng1+/m9dx6c): q jzbmexk2w *lux*ts lq th ($\lambda$, maximum resolvable distance) of 7.0-TeV protons? E =    $\times 10^{-19}\ \text{m}$

  A cyclotron with a radius oi5 * -ezr*hghsf 1.0 m is to accelerate deuterons ($^2\text{H}$, mass $= 2.014$ u) to an energy of 12 MeV.
(a) What is the required magnetic field?$\approx $    T
(b) What frequency is needed for the voltage between the dees?$\simeq $    Hz
(c) If the potential difference between the dees averages 22 kV, how many revolutions will the particles make before exiting?$\approx$    $\ \text{revolutions}$
(d) How much time does it take for one deuteron to go from start to exit? $\Delta t$ =    $ \times 10^{-6}\ \text{s}$
(e) Estimate how far it travels during this time. distance =    m

  The 4.25-km-radius tunnel that will be used to qzb2sqh/ ,e u9house the magnets for the Large Hadron Collider (LHC) calls for proton beams oz,qbhe/s 29qu f energy 7.0 TeV. What magnetic field will be required? B =    T

  The 1.0-km radius Fermilab Tevatron takes about 20 seconds to bring the ene (8.smaj0.r .tpfkczvrgies of the stored protons from 150 GeV to 1.0 TeV. The acceleration is done once per turn. Ef(kv. sc8tpjaz ..0mr stimate the energy given to the protons on each turn. (You can assume that the speed of the protons is essentially $c$ the whole time.) Energy/revolution =    MeV/rev

Show that the energy of a particlvjk)*7klb +6cdj xmuk6w1w.w tray-7 e (charge $e$) in a synchrotron, in the relativistic limit ($v \approx c$), is given by $E\ (\text{in eV}) = Brc$, where $B$ is magnetic field strength and $r$ the radius of the orbit (SI units).

  What magnetic field inc11 (hmqz4yo v: dq eq.z;1b)qxon5qxtensity is needed at the 1.0-km-radius Fermilab synchrotron for 1.0-TeV protons? B = hqnz q v oq1e(q1cx5 .)xmdo y4;:1bqz   T

  How much energy is released in the decai+qngnz 4 f5 x xx ;muuovxx;50e2te28y $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is released whe 7x mndejc 7a5*na+wnfiuww,(k;3;9; jlqv oxn a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to produce a neutron-antineutron pair? p-hvv.1(u+o mrgeug/o-ew6x    MeV

  Estimate the range of the strong force if the mediating pl**u yi619 8-v9 eiqocquxmdrarticle were the kaon instea9xy qv*muiie *rqlc d96-1u8 od of the pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward red:h sie+fvnu6 +.mzz4g3 8 teach other with equal speeds. What minimum kinetic energy must each hit8 f +veu gz4:s+3rendz6.hm ave if a $\pi^0$ meson is to be created in the process? (See Table 32-2.)    MeV

  What minimum kinetic energy must two neutrons kor ,3)-ho(me ki* nb6 skjwhstp +//keach have if they are traveling at the same speed towa n, t-w*jekk3+kobr)6m s/khsp( o /hird each other, collide, and produce a $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak force using Eq. 32-3, givmf c9 ;lqzdv4e*b 8)u8zy nry9en the masses of the W and Z particles as a z98y debn qlru8my)9*cv4zf;bout 80 to $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths of the two photons .v7:y.ay qwgq(snvpu 1)kks:produced when a proton and antiproton atp y1).w:vq.qka svy7g nus k:( rest annihilate? $2m_0c^2$$\approx $    $ \times 10^{-15}\ \text{m}$

The $\Lambda^0$ cannot decay by the following reactions. What conservation law is violated in each of the reactions?
(a) $\Lambda^0 \to n + \pi^0$
(b) $\Lambda^0 \to p + K^-$
(c) $\Lambda^0 \to \pi^+ + \pi^-$

  For the decay $\Lambda^0 \to p + \pi^-$, calculate (a) the Q-value (energy released),Q=    MeV
(b) the kinetic energy of the p and $\pi^-$ assuming the $\Lambda^0$ decays from rest. (Use relativistic formulas.)
$KE_p$ =    MeV
$\text{KE}_{\pi^-}$ =    MeV

Show, by conserving momentum and energy, th+ 2ivdyghg 5 nnja/hx-*o5c1 wat it is impossible for an isolated electron to radiate onyj/ 15 av 5+*ggnox-h2 hicndwly a single photon. (b) With this result in mind, how can you defend the photon exchange diagram in (Fig. Below)?

  What would be the wavelengths of the two photons p8pr1u ,yld*qj 5wvrbb d24zr+roduced when an electron and a positron, l +18q dy2,j u*r5wdvbrp4rbz each with 420 keV of kinetic energy, annihilate head on? $\lambda $ $\approx $    $ \times 10^{-12}\ \text{m}$

  In the rare decay $\pi^+ \to e^+ + \nu_e$, what is the kinetic energy of the positron? Assume the $\pi^+$ decays from rest. $\text{KE}_{\text{e}^-}$ =    MeV

Which of the following reactions and decays are pox8k(.z id;y hvz:b3jissible? For those forbidden, explain wdiy(v3bzk; xjz 8:i.hhat laws are violated.
(a) $\pi^- + p \to n + \pi^0$
(b) $p \to e^+ + \nu_e$
(c) $p + p \to p + e^+ + \pi^+$
(d) $\pi^- \to e^- + \bar{\nu}_e$
(e) $\mu^+ \to e^+ + \nu_\mu$
(f) $p \to n + e^+ + \nu_e$

  Calculate the kinetic energb ap hgzqim8l5,(vl(g:b m,z7y of each of the two products in the decay $\Xi^- \to \Lambda^0 + \pi^-$. Assume the $\Xi^-$ decays from rest.
$\text{KE}_{\Lambda^0}$   MeV
$\text{KE}_{\pi^-}$   MeV

  Could a $\pi^+$ meson be produced if a 100-MeV proton struck a proton at rest? What minimum kinetic energy must the incoming proton have? $\text{KE}_{\pi^-}$ =    MeV

  Calculate the maximum kinetic en7/keh 1 l0:zppf6kix aergy of the electron in the decay $\mu^- \to e^- + \bar{\nu}_e + \nu_\mu$. [Hint: In what direction do the two neutrinos move relative to the electron in order to give the latter the maximum kinetic energy? Both energy and momentum are conserved; use relativistic formulas.] $\text{KE}_{\text{e}^-}$    MeV

  Use (Fig. Below) to estimal;dk 8,w taeh6te the energy width and then the lifetime of the $\Delta$ resonance using the uncertainty principle.
$\Delta E$ =    MeV
$\Delta t$=    $ \times 10^{-24}\ \text{s}$

  The measured width oaz(;j;ucgvd fn2y- wiqe;e ,(f the $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width ogb4a )rcr01 jgf the $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or unced 7 lm j2zdf-8uc7+csgrtainty) of
(a) $\pi^0$, $\Delta E$$\approx$    keV
(b) $\Sigma^0$? (See Table 32-2.) $\Delta E$$\approx$    keV

The $B^-$ meson is a $b\bar{u}$ quark combination. (a) Show that this is consistent for all quantum numbers. (b) What are the quark combinations for $B^+$, $B^0$, $\bar{B}^0$?

Which of the following decays are possible? For those that af-cpc p,f,/vn re forbidden, explain /, v,npcfp- fcwhich laws are violated.
(a) $\Xi^0 \to \Sigma^+ + \pi^-$
(b) $\Omega^- \to \Sigma^+ + \pi^- + \nu$
(c) $\Sigma^0 \to \Delta^0 + \gamma + \gamma$

What are the quark comc sam/8b4k5 eabinations that can form (a) a neutron, (b) an antineutron, (c) a/ ke 85asmc4ba $\pi^+$, (d) a $K^-$?

What particles do the following quark combi. rw.;nd r6rj;cvqm ,tnations produce: (a) $uud$, (b) $uu\bar{d}$, (c) $u\bar{s}$, (d) $\bar{d}u$, (e) $c\bar{s}$?

What is the quark combination neede* l1 p49ha)jea4,uttg i 0klndd to produce a $D^+$ meson ($Q=B=S=0, c=+1$)?

The $D_s^+$ meson has $S=c=+1, B=0$. What quark combination would produce it?

Draw a possible Feynman mt1)i utu4n w;an-1cwdiagram using quarks (as in Fig. Below) for the reaction ;1m14tnwt )ua uciwn-$p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the react+ 1c/ayd)d w+u (jdul ahrcm.-ion $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whose kinetic ene nh 2cs -igr2w 5kkxfivgf6v7e c.;.0yrgy is 25 GeV? What is its wavelength? c2 ;5vgk7r.f y6 xi0c.gf2nkvehw-si
$\approx$    $ \ \text{GeV}$
$\lambda$ $= $    $ \times 10^{-17}\ \text{m}$

  Assume there are $5.0 \times 10^{13}$ protons at 1.0 TeV stored in the 1.0-km-radius ring of the Tevatron.
(a) How much current (amperes) is carried by this beam?I =    A
(b) How fast would a 1500-kg car have to move to carry the same kinetic energy as this beam? v $\approx $    $ \times 10^2\ \text{m/s}$

  Protons are injected into the 1.0-km-radius Fermilab Tevatron with8fb(lnldw 3 8k8jc 0hlr7+n,h t*behyy *s9ln an energy of 150 GeV. If they are accelerated by 2.5 MV each revoluti lr*8l,87 chhlnbted(nw*yl k8yj n 09+h3sf bon, how far do they travel and approximately how long does it take for them to reach 1.0 TeV? d$\approx $    $ \times 10^9\ \text{m}$

  (a) How much energy is released when an electron and a positron annihil2(i l1mvbaw 0iate each othe(lmib0i aw 12vr? $E_{\text{total}}$=    MeV
(b) How much energy is released when a proton and an antiproton annihilate each other? (All particles have $KE = 0$.) $E_{\text{total}}$ =    MeV

Which of the following reactions are possiblrx (j;yr;w.e+c o8xm3yh.atk;x nq:me, and by what interaction could they occur? For those forbiddennx.a o:8.;rew3m kxmj(cyh+;x ;t yqr, explain why.
(a) $p + \pi^- \to K^+ + \Sigma^-$
(b) $p + \pi^+ \to K^+ + \Sigma^+$
(c) $p + \pi^- \to \Lambda^0 + K^0 + \pi^0$
(d) $p + \pi^+ \to \Sigma^0 + \pi^+$
(e) $p \to \pi^+ + e^- + \bar{\nu}_e$

Which of the following reactions are possible, and by what interan ,z 97,+burkmt/ vzufction could they occur? For those forbiddentr7 +,/zbzumf,v9 nuk, explain why.
(a) $p + \pi^- \to K^0 + p + \pi^0$
(b) $p + K^- \to \Lambda^0 + \pi^0$
(c) $n + K^+ \to \Sigma^+ + \pi^0 + \gamma$
(d) $K^- \to \pi^- + \pi^0 + \pi^+$
(e) $\pi^+ \to e^+ + \nu_e$

One decay mode for ah fyme-q(0 z(b $\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occurs in the ecb :8 q nf ;s8hd8xyybpwco/,.lectroweak theory at about $10^{-18}\ \text{m}$. Show that this corresponds to an energy that is on the order of the mass of the W boson ($M_W c^2 \approx 80\ \text{GeV}$). $mc^2$$\approx$   GeV

  The mass of a $\pi^0$ can be measured by observing the reaction $\pi^- + p \to \pi^0 + n$ at very low incident $\pi^-$ kinetic energy (assume it is zero). The neutron is observed to be emitted with a kinetic energy of 0.60 MeV. Use conservation of energy and momentum to determine the $\pi^0$ mass. $E_{\pi^0}$ =    $MeV/c^2$

  Calculate the Q-value for each of the reactions, Eq. 32-4, for producing a pionlj:s q2ah.gtix . mo93. ogth9xj.a3 2:lmq . si$Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value for ntzt-4u1b hy;ue1b 4ethe reaction $\pi^- + p \to \Lambda^0 + K^0$ when negative pions strike stationary protons. Estimate the minimum pion kinetic energy needed to produce this reaction. [Hint: Assume $\Lambda^0$ and $K^0$ move off with the same velocity.]
Q =    MeV
$\text{KE}_{\pi^-}$ =    MeV

  How many fundamental fermions are there in a water(+ zw ,cj05qvw zh9y9a ovdg8esg9v4b molecule?    fermions

  A proton and an antiproton annihilate each other at rest nvml(s//0vho o b-k-band produce two pions, sh(0o-vn /bvl/om b-k$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called ustanv// ey:t .nification distance of $10^{-31}\ \text{m}$ in grand unified theory is equivalent to an energy of about $10^{16}\ \text{GeV}$. Use the uncertainty principle, and also de Broglie's wavelength formula, and explain how they apply. $\Delta E$ =    $ \times 10^{16}$GeV E =    $ \times 10^{15}$
(b) Calculate the temperature corresponding to $10^{16}\ \text{GeV}$. E =    $10^{28} K$

For the reaction $p + p \to 3p + \bar{p}$, where one of the initial protons is at rest, use relativistic formulas to show that the threshold energy is $6m_p c^2$, equal to three times the magnitude of the Q-value of the reaction, where $m_p$ is the proton mass. [Hint: Assume all final particles have the same velocity.]

  The lifetimes listed in Table 32-2 .t8 4c 8tar95bht5nres hstvmq ;f8,iare in terms of proper time, measured in a reference frame where the particl5t8.hatmbt tre8;c54i hf9 ,s s nv8qre is at rest. If a tau lepton is created with a kinetic energy of 450 MeV, how long would its track be as measured in the lab, on average, ignoring any collisions? $\Delta x_{\text{lab}} = $    $ \times 10^{-5}\ \text{m}$

Identify the missing particle in ij:ffv27 r:, smut d2xthe following reactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to describe the rpvq30 clg/w1veaction $p + n \to \pi^+ + \pi^-$.

What fraction of the spee91blf4rvjryz7q n-: : cc bk:fd of light $c$ is the speed of a 7.0-TeV proton?